Data traffic congestion is a common problem in computer networks. Conventional congestion control methods include Transmission Control Protocol (TCP) congestion control, such as Random Early Detection (RED), Weighted RED (WRED), and Quantized Congestion Notification (QCN), which is standardized as Institute of Electrical and Electronics Engineers (IEEE) Standard 802.1 ua-2010. Both of these congestion control methods rely on rate adaption of the source based on feedback from the congestion point within the network. For RED congestion control, the feedback indicating congestion is typically provided by using packet discard. For QCN congestion control, the feedback indicating congestion includes explicit information about the rate of overload and the information is delivered to the flow source using a backward congestion notification message.
These and other conventional congestion control methods require relatively long times to settle a flow to a stable rate. With the delay bandwidth product of networks increasing more rapidly than the available switch buffer and with large transient traffic loads, these conventional congestion control methods do not provide adequate buffer control for high speed networks, such as datacenters.